Friction-clutch



(No Model.)

0. CROSBY.

FRICTION CLUTCH.

Patented Apr. 22, 1890.

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UNITED STATES PATENT OFFICE.

OLIVER CROSBY, OF ST. PAUL, MINNESOTA.

FRICTION-CLUTCH.

SPECIFICATION forming part of Letters Patent No. 425,989, dated April 22, 1890.

Application filed January 4: 1890- Serial No. 335,914. (No model.)

To all whom it may concern:

Be it known that I, OLIVER CROSBY, of St. Paul, Ramsey county, Minnesota, have invented certain Improvements in Friction- Olutches, of which the following is a specification.

My invention relates to brakes or clutches employed in various kinds of machinery, particularly hoisting machinery, by means of which intermittent motion may be imparted to a part of the machinery from a constantlyrunning portion having connection therewith-as, for example, to the cable-carrying drum loosely arranged upon a constantlyrunning shaftfrom the shaft; and it consists, generally, in arranging upon said shaft a sliding sleeve carrying fulcrum-arms, which are connected to suitable brakes or clutches adapted to engage with said loose drum, and by frictional contact therewith to transmit the motion of the shaft thereto when thrust outward by the sliding motion of the sleeve.

My invention further consists in the construction and combination hereinafter described, and particularly pointed out in the claims.

In the accompanying drawings, forming a part of this specification, Figure 1 is an end elevation of the driving gear-wheel and its shaft fitted with my improvements, the end of the drum loosely journaled on the shaft being shown by dotted lines. Fig. 2 is a plane view and partial section, on line as 00 of Fig. 1, of the same, showing the manner in which the brakes are operated by means of the sliding sleeve to which they are connected. Fig. 3 is a detail of the circular spring, by means of which the brakes are drawn out of engagement with the drum.

In the drawings, 2 represents the main or driving shaft, journaled in suitable bearings 3, secured to the frame or support 4:. Rigidly secured upon the shaft is the driving gear- Whcel 5, by means of which motion is transmitted to the shaft from any suitable source of power. Loosely journaled upon the shaft 2 is the drum (3, upon which the cable or rope is wound when used as a hoisting apparatus. The rim 7 of the drum is formed with an inner peripheral V-shaped groove, into which the brake-shoes 8, whose exterior surfaces are conformed to the size and shape of the groove,

are adapted to fit. Suitably secured upon the shaft 2, by means of the key 10, passing through a slot in the same and through the longer slot 24: in the shaft, is the sleeve 9, to which are pivotally connected the fulcrumarms 11, which are at their opposite ends pivotall y connected to the brake-frames 14. The brakes are each formed, preferably, with a main frame 1 1, having sockets 12, into which are fitted the brake-shoes 8. These shoes I prefer to make of hard wood, with the grain of the wood arranged endwise to the groove or radially as to the drum and secured in their sockets in any suitable manner, as by means of bolts 13, passing through the same and through the bottom of the socket. The brake-shoes are preferably made of two pieces, together formingabout a quadrant, each brake having a fulcrum-arm, as shown by the dotted lines of Fig. 1, in which only one brake is represented, the others being removed. The frame 11 is arranged to slide upon the spokes 15 of the wheel 5, the gibs l6, bolted to said frame, overlapping the spokes and bearing upon the raised portions or guides 33, so as to hold thebrake-frame firmly against the opposite face of the spokes. In order that the brakes may be held normally out of engagement with the drum,I prefer to provide the circular clasp-spring 17, which is secured to the several brake-frames, preferably by means of bolts 1.8 and 19, passing through the frames and serving as studs against which the spring bears, the bolt 18 passing through an eye in one end of the spring and firmly securing it in place, and the bolts 15) passing through the brake-frames only and serving for supports for the spring which inclasps them, its free end 20 overlapping its secured end. I prefer to arrange upon the bolts 19 the bushings 21 and 22, formed of iron pipe, the bushing 21 fitting closely upon the bolt and inside the bushing 22, the bushing 21 being slightly longer than bushing 22, and thus serving to form a rigid shoulder or support for the bolt-head or nut at one end and the brake-framo at the other when the bolt is screwed tight, while leaving the bushing 22 free to turn upon it as an antifrietion roll as moved by contact with the sprin The adj ustmont of the spring to the brakes is such that the tension of the spring tends to withdraw the brakes from the groove, and thus prevent their touching the drum, which is an important feature, as the shoes tend at times to stick in the grooves, so as to require considerable force to free them.

In order to assist the spring 17 in automatically disengaging the brakes from the drum, I provide the springs 34, rigidly secured at one end to the gear-wheel 5,with the opposite end bearing against the sleeve 9 and tending to force it outward from the wheel. Other forms or arrangements of springs may be employed, if desired, to serve the same purpose; but the forms shown I prefer for their simplicity and efficiency.

The fulcrum-arms 11 are pivoted at 27 to the brake-frame and at 28 to the sleeve, forming less than a right angle with the shaft, the sleeve being outside of the gear-wheel. Consequently if the sleeve be moved toward the wheel the arms will approach a vertical position with reference to the shaft, and thus thrust the brakes outward radially into the groove of the drum, while if the sleeve be released the springs 17 and 34 will co-operate to throw it outward and contract or draw inward the brakes.

The arms 11 are each fitted with the interior screw 25, threaded into the end of the arm and provided with the jam-nut 26. The length of the arms is varied at will by removing the pivot-pin 28, when the screw can be given a half-turn in either direction and then secured by the pin. The arms are thus lengthened or shortened equally by the same number of turns or partial turns and the brakes adjusted to exactly the desired normal position or length and the wear upon the shoes compensated or taken up.

In order to slide the sleeve 9 upon the shaft, so as to force the brakes outward, I prefer to bore out the end of the shaft 2 to receive a rod 23, which extends inward far enough to bear upon the key 10. This key is tightly fitted into the sleeve 9, but slides freely in the slot 24, longitudinally of the shaft, the slot 24 being longer than the width of the key. As the rod 23 is advanced into contact with the key, it carries the key forward or toward the drum, thus advancing the. sleeve along the shaft.

The rod 23 may be manipulated in any desired manner; but I prefer to drive it by means of a screw 30, secured to or made integral with it and threaded into a hub or other firmly-secured support 31, and provided with a crank 32, by means of which it may be turned and the rod thus advanced or withdrawn.

Any desired number of brakes maybe used; but I prefer to fit the wheel with four. As shown in Fig. 1, only one brake is indicated in place, the others being removed, disclosing the raised portions or guides 33 on the spokes, along which the gibs 16 slide.

In operation the wheel 5 and its shaft 2 are driven continuously by any suitable power, the shaft turning freely in the drum 6, which remains stationary, the brakes being held out of engagement with it by the spring 17. When it is desired to rotate the drum with the shaft, the crank or handle 32 is turned forward, advancing the screw 30 and the rod 23 into the shaft until it bears upon the key 10, carrying it forward with its sleeve upon the shaft. The fulcrum-arms are thus pressed outward, moving the brake-frames along the spokes of the gear-wheel and forcing the brake-shoes firmly into the groove of the drum. The friction thus caused between the brake-shoes and the groove serves to clutch them together, and thus cause the drum to rotate with the shaft. By reversing the motion of the crank the rod 23 is withdrawn from the key, thus freeing the sleeve from outward pressure, when the pressure of the spring 34 upon the sleeve and of the spring 17 upon the brake-frames withdraws them from the rim of the drum and forces the sleeve outward along the shaft, thus releasing the drum from the clutch and allowing it to come to rest or to be rotated in the opposite direction upon the shaft.

It is apparent that slight modifications in construction may be made without departing from the principle of myinve11tio'n-as, for example, in employing a different device for shifting the sliding sleeve where the adjacent end of the shaft is not accessible.

I claim- 1. In a friction-clutch, the combination of the main shaft, a sliding sleeve secured upon said shaft, brakes supported upon said shaft and adapted to be moved radially, pivoted ful crum-arms connecting said brakes and said sliding sleeve, meansfor advancingsaid sleeve along said shaft so as to operate said brakes, and means for automatically withdrawing said brakes and reversing the movement of said sleeve when released, substantially as described.

2. The combination of a continuously-running shaft, a loose drum or wheel journaled upon the same, having an inner peripheral \l-shaped groove, brakes supported upon said shaft and adapted to be radially moved into said groove, a sliding sleeve secured upon said shaft, having fulcrum-arms connecting it with said brakes, means for forcing said sleeve toward said brakes, and springs engaging said sleeve and said brakes and tending to withdraw the brakes from said groove,

substantially as described.

3. In a friction-clutch, the combination of a hollow slotted shaft, a sleeve slidably secured upon said shaft by means of a key passing tending to move the same toward the shaft, substantially as above set forth.

4. The combination, in a friction-clutch having radially'sliding brakes, of a sliding sleeve arranged upon the driving-shaft, pivoted arms connecting said brakes to said sleeve, means for advancing said sleeve on said shaft toward said brakes, springs bearing against said sleeve and tending to force it outward, and a clasp-spring engaging studs on said brakes and tending to move the same toward the shaft, substantially as described.

5. The combination, in a friction-clutch, of radiallysliding brakes, studs upon said brakes, rolling bushings upon said studs, and

a circular clasp-spring enclasping said studs and tending to automatically move said brakes toward the shaft, substantially as de scribed.

(S. The combination, with the wheel 5, its shaft, and the drum 6, journaled on said shaft, of a series of brakes arranged to -slide upon the spokes of said wheel and into frictional contact with the rim of said drum, the sliding bushings upon said fixed bushings adapt-ed to be turned by the sliding contact of the claspspring, substantially as and for the purposes set forth.

In testimony whereof, I have hereunto set my hand this 30th day of December, 1889.

OLIVER CROSBY. lVitnesses:

T. D. MERWIN, W. B. ROBERTS. 

